SNP ministers slashed funding for the body responsible for maintenance of the Forth Road Bridge despite warnings that the move would increase risks to its structural integrity, it has emerged.

At First Minister's Questions, Nicola Sturgeon was urged to take responsibility for the current crisis, which has seen one of the country's most important routes closed until the new year after engineers spotted a crack in a steel truss close to its north tower.

Kezia Dugdale, the Scottish Labour leader, highlighted minutes from a 2013 meeting of the Forth Estuary Transport Authority (Feta), stating that the Scottish Government's September 2011 Spending Review resulted in a 58 per cent reduction its capital funding and, as a result, a number of projects were deferred to beyond 2015.

The minutes went on to state: "That deferral of part or all of these projects does increase the risk to the long term structural integrity of the bridge."

Ms Dugdale said: "Crucially, the truss end link work was one of the projects that were delayed. Key projects were delayed because of SNP Government cuts - short-term decisions that were made at the expense of the long-term future of an important national asset."

Earlier this week, transport minister Derek Mackay said that the fault that led to the bridge's closure had not been in an area scheduled for repairs five years ago. However, the following day he admitted that scrapped 2010 works would have replaced the damaged section.

The Scottish Conservatives also seized on the confusion with Ruth Davidson, the party's leader, calling on John Swinney to announce a reversal of cuts to the bridge's maintenance allocation in his budget next week.

She said: "The First Minister cannot avoid the fact that the budget for the Forth Road Bridge has been hammered in recent years... It is clear that the authorities gambled that the old bridge could be patched up until the new one was opened. Now we know that that gamble failed."

Ms Sturgeon said that the Government would co-operate fully with any inquiry into the closure, should one be launched by any parliamentary committee at Holyrood.

Audit Scotland, in a report it published in 2012, said that Feta's three year capital grant had been cut by 65 per cent. Yesterday, engineers said they know how to repair the Forth Road Bridge, which is usually crossed by 70,000 vehicles a day, although the fix is not a long-term solution. The repair solution involves a plate welded repair to the damaged truss end link and jacking the link in position.

While it is anticipated that the bridge will reopen early in the new year, Ms Sturgeon acknowledged that the work will be "heavily weather dependent."

The First Minister said that her government had displayed "foresight" by commissioning the replacement Forth crossing, which is due to open late next year. She also repeatedly said that the section of the bridge that had caused the current closure was not broken when the previous works were shelved.

She added: "The specific part of the bridge that is being repaired now was not broken back in 2010; the work that was considered in 2010 was prompted by concern about another part of the truss end link, not the part that is now cracked. The work that was considered in 2010 would have been a more extensive repair than was required, and it would have completely closed the bridge for a number of weeks.

"That is why the Forth Estuary Transport Authority - not the Scottish Government - which was made up of councillors from all parties, decided to do further analysis and proposed a more proportionate repair. That more proportionate repair was under way when the current defect was identified.

"What was Labour’s position on building a new Forth replacement crossing? James Kelly, Labour’s infrastructure spokesperson at the time - the person who was jumping up and down in the chamber yesterday, complaining that we had not fixed a crack five years before the crack appeared - said of the new Forth replacement crossing: 'from the start this has been a vanity project for the Scottish Government.'

"It was those on the Labour benches, not the Scottish Government, who wanted to save money on making sure that people could continue to travel across the Forth."